Radiation Hardening by the Modification of Shallow Trench Isolation Process in Partially Depleted SOI MOSFETs

Two radiation hardening processes for shallow trench isolation (STI), i.e., Si
⁺
implantation and STI oxide nitridation are investigated, including the impact on nominal electrical characteristics and radiation hardness. The total ionizing dose effects of the nMOS devices are proved to be sensitive to the STI radiation hardening process conditions. There are optimum process conditions to achieve the best effectiveness of radiation hardening. Then, a 130-nm radiation-hardened PDSOI technology has been developed. The radiation hardness is verified by static random access memories with small storage capacities.